%0 Journal Article
%T Double-lattice photonic-crystal resonators enabling high-brightness semiconductor lasers with symmetric narrow-divergence beams
%J -
%D 2018
%R https://doi.org/10.1038/s41563-018-0242-y
%X Achieving high brightness (where brightness is defined as optical power per unit area per unit solid angle) in semiconductor lasers is important for various applications, including direct-laser processing and light detection and ranging for next-generation smart production and mobility. Although the brightness of semiconductor lasers has been increased by the use of edge-emitting-type resonators, their brightness is still one order of magnitude smaller than that of gas and solid-state/fibre lasers, and they often suffer from large beam divergence with strong asymmetry and astigmatism. Here, we develop a so-called ¡®double-lattice photonic crystal¡¯, where we superimpose two photonic lattice groups separated by one-quarter wavelength in the x and y directions. Using this resonator, an output power of 10£¿W with a very narrow-divergence-angle (<0.3¡ã) symmetric surface-emitted beam is achieved from a circular emission area of 500£¿¦Ìm diameter under pulsed conditions, which corresponds to a brightness of over 300£¿MW£¿cm£¿2£¿sr£¿1. In addition, an output power up to ~7£¿W is obtained under continuous-wave conditions. Detailed analyses on the double-lattice structure indicate that the resonators have the potential to realize a brightness of up to 10£¿GW£¿cm£¿2£¿sr£¿1, suggesting that compact, affordable semiconductor lasers will be able to rival existing gas and fibre/disk lasers
%U https://www.nature.com/articles/s41563-018-0242-y